After having been worn out, a piston ring and a cylinder liner are subject to an insufficient sealing betweenwith, and an insufficient compression in the cylinder, whereby resulting in, when an engine is running, a waste of fuel, a reduced power output, as well as difficulty to cold restarting of a stopped engine. In the internal combustion engine industry, piston rings are considered to be parts that wear out quickly. The efforts for increasing the service life of piston rings have been concentrated on improvement in anti-abrasion materials and producing processes for manufacturing them. But insufficient sealing is mainly caused by worn-out liners or rings. The piston rings replaced frequently because they wear out replacing the piston rings required, wherein dismounting and then mounting the engine, resulting in a waste of time and labor and influences its service. The inventors of this invention provided a piston compression ring assembly as a solution to overcome the above problems (China Patent No. 75790). However, the lubrication of the assembly, is not good enough, and also needs further improvements.